Chances are if you’ve ever suffered a lower extremity injury, someone has told you that it was because you pronate when you walk or run. While it is true that you pronate with each step, it is not necessarily true that it is because of pronation. This blog post will discuss the normal gait cycle and why pronation may not be the reason for your pain.
The typical gait cycle is divided into a stance and swing phase. The stance phase begins when the foot makes contact with the ground (usually the heel is the first part to strike the ground when walking). The foot then goes into mid stance which is when the foot is flat on the ground. The final phases of the stance phase is heel lift and toe off. The leg then transitions to the swing phase before repeating the gait cycle once the foot returns to the ground.
Pronation is the term used to describe the combination of three motions: abduction, eversion, and dorsiflexion of the foot. The opposite of pronation is supination (adduction, inversion, and plantarflexion). Normally, the foot pronates during early stance phase. This unlocks the bones in the foot, allowing you to absorb some of the ground-reactive forces. Pronation also internally rotates your tibia allowing the knee to flex, which allows the quadriceps to absorb most of the ground forces. As you move from heel strike to toe off, the foot transitions from pronation to supination. Supination locks the joints in the foot together so that you can have a powerful toe off phase.
The problem with blaming pronation as the cause of an injury is that it provides an overly simplistic view of the injury. If pronation is the issue, it would make sense to limit pronation with a motion control shoe or an orthotic. However, the research suggests that subtalar motion (pronation) and pronation control shoes are not effective in decreasing injury rates in runners.
Instead, the focus should be on improving the motor control and strength of the foot itself. Poor motor control of the foot allows the foot to either rapidly pronate or stay pronated for too long in the gait cycle. Rapid pronation would increase the force to the inside arch of the foot (good ole force = mass * acceleration) which could cause an injury. The duration of pronation is also problematic becauseduring heel lift and toe off the foot would not be locked in supination. As a result, the foot would act as an ineffective lever causing either the calf to compensate to generate more force or an early lift off of the foot.
To improve the strength and motor control of the foot, common exercises include: toe dexterity, short foot, towel crunches, and heel lifts.
- The toe dexterity exercise is when you lift your 4 smaller toes up while keeping the big toe on the ground, then reversing the motion. This exercise improves the motor control of the flexors and extensors of the foot.
- The short foot exercise is where you lift the inside of your arch by approximating the first metatarsal head and heel. This helps build the strength of the small intrinsic muscles of the foot.
- Towel crunches build the small toe flexors of the foot that are responsible for supporting the inside arch. Take a towel and crunch your toes, which will pull the towel towards you.
- Heel lifts are a simple exercise that will increase the strength of the tibialis posterior muscle (one of the main supporting muscles of the inside arch). While standing, slowly raise your heel off the ground then lower it to the ground. To make this more difficult, try it while standing on one leg.
Unfortunately, pronation typically has a bad reputation in running related injuries. However, blaming pronation for these injuries is an over simplification of how these injuries occur. Hopefully this article sheds some light on the misunderstood movement.
Nielsen, Rasmus Oestergaard, Ida Buist, Erik Thorlund Parner, Ellen Aagaard Nohr, Henrik Sørensen, Martin Lind, and Sten Rasmussen. "Foot Pronation Is Not Associated with Increased Injury Risk in Novice Runners Wearing a Neutral Shoe: A 1-year Prospective Cohort Study." British Journal of Sports Medicine Br J Sports Med 48.6 (2013): 440-47.